1. Technical Field
Various embodiments of the present invention relate to a semiconductor apparatuses and related methods. In particular, certain embodiments related to a technology for constructing a voltage regulator.
2. Related Art
A semiconductor apparatus typically receives an external power to generate internal voltages with various voltage levels, and operates internal circuits using the internal voltages. The semiconductor apparatus regulates the internal voltages according to specific use. For example, in a flash memory device, since the level of a voltage applied to word lines is regulated according to a specific operation mode, an output voltage for performing a specific operation using a voltage regulator is output to the word lines.
FIG. 1 is a configuration diagram of a typical voltage regulator.
Referring to FIG. 1, the voltage regulator may include a voltage output unit 10 and a resistance division unit 20.
The voltage output unit 10 outputs an output voltage VPGMERA to a voltage output terminal NO. The voltage output unit 10 includes a comparator 11, which compares a divided voltage V_DIV with a reference voltage VREF and outputs a control voltage V_CTRL based on a comparison result, and a voltage driver 12 which outputs the output voltage VPGMERA with a level corresponding to the level of the control voltage V_CTRL to the voltage output terminal NO.
The resistance division unit 20 includes a plurality of first resistors R0 and R1_0 to R1_146, a plurality of switches MN0 to MN146, and a reference resistor R2. The plurality of first resistors R0 and R1_0 to R1_146 are coupled in series between the voltage output terminal NO and a first node L1. Each of the plurality of switches MN0 to MN146 is coupled between one end of each of the plurality of first resistors R0 and R1_0 to R1_146 and the first node L1, respectively, and is selectively turned on in response to control codes S0 to S146. The reference resistor R2 is coupled between the first node L1 and a ground voltage terminal VSS.
The voltage level of the output voltage VPGMERA output through the voltage output terminal NO is regulated according to the ratio of a divided resistance value R3 determined through the resistance division unit 20 and a resistance value of the reference resistor R2. That is, when the plurality of switches MN0 to MN146 are selectively turned on according to the code values of the control codes S0 to S146, one or more first resistors R0 and R1_0 to R1_146 are selected, so that the divided resistance value R3 is determined. The voltage level of the output voltage VPGMERA increases as the divided resistance value R3 increases.
Meanwhile, in order to expand a regulation range of the output voltage VPGMERA or more precisely regulate the voltage level of the output voltage VPGMERA, the number of the switches and the resistors comprising the resistance division unit 20 should increase. However, if the number of the switches increases, the number of bits of the control codes for controlling the switches should also increase. Since the control codes are generated through level shifts, the number of the level shifts should also increase. Since the typical voltage regulator as described above occupies a large area, a technology for solving such problem is necessary.